JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="sec">
									<li><a href=""  data-link="cat1">1</a></li>
									<li><a href=""  data-link="cat2">2</a></li>
								</ul>
								<ul class="third" data-menu="cat1">
									<li><a href="">1111111111111111</a></li>
									<li><a href="">11111 штука</a></li>
									<li><a href="">111 11 11</a></li>
								</ul>
                <ul class="third" data-menu="cat2">
									<li><a href="">222</a></li>
									<li><a href="">22222 22</a></li>
									<li><a href="">22 22 22</a></li>
									<li><a href="">22 штука</a></li>
								</ul>

JavaScript

$(document).ready(function(){
$('.third').fadeOut();
	function subMenu() {
		var link = $(".sec>li>a");
		var flag = false;
		var data,activeMenu;
		
		link.hover(
			function(){
				data = $(this).data('link');
				activeMenu = $('.third[data-menu="'+data+'"]');

				$('.third').stop().hide();
        activeMenu.stop().fadeIn();
				
			},
			function(){
				
			});

		
	}

	subMenu();


});